Name of the disease: HIV (Human Immunodeficiency Virus). HIV is a virus that attacks the body’s immune system. It is separate from AIDS, which is a condition that can be caused by having HIV for a long time. AIDS (Acquired Immunodeficiency Syndrome) is when the immune system becomes too weak to fight infections.

Common/Uncommon:1.5 per 1,000 people in the population (1.0 in women and 2.1 in men) are living with HIV and an estimated 21,900 people living with HIV were unaware of their infection, roughly 1 in 4. Effective HIV medication means people often recover from AIDS-related illnesses..

Severity: A lot of people may think HIV is life-threatening. In some cases, particularly when a person is not treated, it can be, as there is no cure. However current treatment is highly effective and allows many people with HIV to live long and healthy lives. Recently, doctors became so good at treating HIV that HIV positive people can live the same amount of time as those without. It is still important to realise that the earlier HIV is diagnosed, the better the outcome as treatment can control it sooner.

The HIV virus weakens the immune system, making it harder for the body to fight infection. If left untreated HIV positive people may develop AIDS. At this point, it is very difficult for a person to fight simple infections like a cold and stomach bugs that are part of a range of infections or conditions the body would usually cope with, which may be life threatening (like TB and pneumonia).

How it is transmitted: in 95% of cases HIV is transmitted through either anal or vaginal sex without a condom, though HIV can also be transmitted from sharing needles, and through direct contact with infected blood on to an open wound of your own, however direct contact transmission is extremely rare. It is much less commonly transmitted via oral sex or sharing sex toys. To limit the risk of HIV being transmitted via oral sex, use condoms or avoid oral sex if you have cuts or sores in your mouth or bleeding gums.HIV can be transmitted to a baby during pregnancy, birth or breast feeding, though with the right planning and medical treatment, HIV positive mothers very rarely transmit the virus to their babies. Recent studies show with treatment the risk of HIV being transmitted from mother to baby an is less than 1%. It is even less commonly transmitted through blood donor products as many safety measures are taken to stop this from happening so that being given blood is very safe.

It is important to mention that HIV cannot be transmitted through sweat, saliva or urine, so it is not transmitted via kissing, sharing a bath, being sneezed on or being in a swimming pool with a positive person.

If the person living with HIV is diagnosed and on successful treatment it is very unlikely that the virus will be transmitted to sexual partners. If someone thinks they have been exposed to HIV, they can also get immediate treatment to reduce the chance of HIV transmission occurring (see PEP in the section below about treatment).

For penetrative sex, condoms are the most effective protection against HIV but are not 100% effective and need lubrication for anal sex. The correct lubrication to use is water-based or silicone-based, as other types of lubrication can damage the condom making it more likely that it will split during sex. To reduce the risk of contracting HIV, it is important to use condoms every time you have sex

Symptoms: A few weeks after transmission of HIV, some people may experience a flu-like illness although this does not happen to everyone. Around 70-90% of people will experience some form of symptoms within the first 10 to 14 days from exposure. There are many different possible symptoms and they are best explained by the NHS HIV page, with the stages of the infection explained well by THT.

Many people get HIV and have absolutely no symptoms and can remain this way for many years, but during this time, the virus is damaging the body's immune system and could be transmitted to sexual partners. Around 1 in 4 with HIV don’t know that they are infected (2013 figures) so the only way to know if you have HIV for sure is to get tested. You can find your closest rapid HIV testing centre on the SXT website.

Testing: HIV testing is very reliable and can detect the virus after one month of infection. The test cannot detect the virus before this time. There are a number of different blood tests available but the most accurate HIV tests are known as 4th generation laboratory tests. With laboratory tests,it is recommended that the results are made available as soon as possible and preferably within 48 hours.

Another type of test is known as a Point of Care Test or a “rapid test” which uses a very small amount of blood from a finger prick and gives indicative results in a matter of minutes. Depending on the result of this test, a further blood test is needed to diagnose HIV. The difference in this test is that it is only reliable after 12 weeks from exposure, so before this time a laboratory test, as mentioned before, will provide an accurate result sooner.

POCT tests can be performed at most sexual health clinics, some GPS and clinics run by charities (eg the Terrence Higgins Trust) and in many community settings. They are normally free of charge.You can find your closest rapid HIV testing centre on the SXT website.

Treatment:The treatment for HIV involves a combination of tablets known as ‘antiretroviral therapy’ which works by stopping the virus from replicating, which prevents it from damaging the immune system.

Emergency HIV drugs: For some people who come into contact with HIV, a different medication may be used to try and stop the infection in the very early stages. This is called ‘PEP’ (Post Exposure Prophylaxis) and is most effective when taken as soon as possible after exposure (ideally less than 24 hours). It is unlikely to work if started more than 72 hours after exposure. The tablets are taken for 28 days and can have some side effects. Though in most cases it works well, there is no guarantee PEP will work. These tablets are available from Sexual health clinics and A&E.

There is also the development of a new type of prevention to HIV: Pre-Exposure Prophylaxis (PrEP). This is an exciting area of giving medicines to those at high risk of getting HIV to stop them being infected in the future, that is best explained by PrEP Access.

More information:

Information about HIV is changing all the time, at the time of writing (January 2015) this information is accurate though more information can be found by following the links below.